(1) Field of the Invention
The present invention relates to open end spinning rotors for spinning devices. More specifically, the present invention is directed to open end spinning rotors of the type which are rotated at relatively high speeds and are subjected to relatively high centrifugal forces.
(2) Description of the Prior Art
Spinning rotors used in open end spinning devices are rotated at relatively high speeds. Because of the relatively high rotational speeds, the peripheral wall of the rotor is subjected to tremendous centrifugal forces. Since the rotor must have sufficient strength to resist the centrifugal forces, prior art rotors are machined from a metal such as aluminum. It should be understood that it is relatively difficult to machine metal in comparison to plastic, and, further, metal is generally more expensive than plastic.
Because of the relatively high rotational speeds, a relatively large amount of friction is generated between the metal which bounds the fiber collection groove and the fibers which are collected in the groove. In order to reduce wear of the metal rotor and to increase the useful life of the rotor, a rotor is typically coated with a hard, wear resistant coating such as a ceramic coating, diamond coating or metal plating. It should be understood that this coating is costly to apply and also subject to damage such as chipping. Damage to the coating renders the rotor practically useless and the rotor must be replaced.
Because of the relatively heavy weight, metal rotors consume more power than a rotor having a lighter weight would consume. Also, due to the friction between the surface coating on the metal rotor and the fibers, the surface of the rotor tends to collect debris. It should be understood that the fibers which are drawn through the spinning rotor, whether natural or synthetic, may include additives which effect the properties of the yarn produced. The additives may be included, for example, to improve the luster of the yarn or to improve the strength properties of the yarn. During spinning of the fibers, debris may form on the surface of the rotor, the debris being the fiber additives and minute particles of fiber broken from the fibers. A small amount of debris will significantly effect the wear properties of the rotor.
It is an object of the present invention to provide a rotor which may be made, at least partially, of a plastic material. It is another object of the present invention to provide a rotor wherein the material which bounds the fiber collection groove generates reduced friction in comparison with metal. It is a further object of the present invention to provide a rotor which resists deformation as a result of centrifugal forces generated by rotation of the rotor at relatively high speeds.